Dirty PoC implem of caching.

Author: beauby

lib/jsonapi/renderer.rb

@@ -20,6 +20,6 @@ module JSONAPI
   #   @option [Hash] links Top-level links to be included.
   #   @option [Hash] jsonapi_object JSON API object.
   def render(params)
-    Renderer::Document.new(params).to_hash
+    Renderer::Document.new(params).to_json
   end
 end

lib/jsonapi/renderer/document.rb

@@ -14,39 +14,44 @@ def initialize(params = {})
         @include = JSONAPI::IncludeDirective.new(params.fetch(:include, {}))
       end
 
-      def to_hash
-        @hash ||= document_hash
+      def to_json
+        @json ||= document_hash
       end
-      alias to_h to_hash
 
       private
 
       def document_hash
-        {}.tap do |hash|
-          if @data != :no_data
-            hash.merge!(data_hash)
-          elsif @errors.any?
-            hash.merge!(errors_hash)
-          end
-          hash[:links]   = @links    if @links.any?
-          hash[:meta]    = @meta     unless @meta.nil?
-          hash[:jsonapi] = @jsonapi  unless @jsonapi.nil?
+        parts = []
+        if @data != :no_data
+          parts.concat(data_hash)
+        elsif @errors.any?
+          parts << errors_hash
         end
+        parts << "\"links\":#{@links.to_json}"      if @links.any?
+        parts << "\"meta\":#{@meta.to_json}"        unless @meta.nil?
+        parts << "\"jsonapi\": #{@jsonapi.to_json}" unless @jsonapi.nil?
+
+        parts.any? ? "{#{parts.join(',')}}" : ''
       end
 
       def data_hash
         primary, included =
           ResourcesProcessor.new(Array(@data), @include, @fields).process
-        {}.tap do |hash|
-          hash[:data]     = @data.respond_to?(:each) ? primary : primary[0]
-          hash[:included] = included if included.any?
+        [].tap do |arr|
+          data = if @data.respond_to?(:each)
+                   "[#{primary.join(',')}]"
+                 elsif @data.nil?
+                   'null'
+                 else
+                   primary.first
+                 end
+          arr << "\"data\":#{data}"
+          arr << "\"included\":[#{included.join(',')}]" if included.any?
         end
       end
 
       def errors_hash
-        {}.tap do |hash|
-          hash[:errors] = @errors.map(&:as_jsonapi)
-        end
+        "\"errors\":[#{@errors.map(&:as_jsonapi).map(&:to_json).join(',')}]"
       end
 
       def _symbolize_fields(fields)

lib/jsonapi/renderer/resources_processor.rb

@@ -1,19 +1,33 @@
 require 'set'
 
+class Cache
+  def initialize
+    @cache = {}
+  end
+
+  def fetch_multi(keys, &block)
+    keys.each_with_object({}) do |k, h|
+      @cache[k] = block.call(k) unless @cache.key?(k)
+      h[k] = @cache[k]
+    end
+  end
+end
+
 module JSONAPI
   module Renderer
     class ResourcesProcessor
       def initialize(resources, include, fields)
         @resources = resources
         @include   = include
         @fields    = fields
+
+
+        @cache = Cache.new
       end
 
       def process
         traverse_resources
-        process_resources
-
-        [@primary, @included]
+        [@primary, @included].map { |res| process_resources(res) }
       end
 
       private
@@ -72,14 +86,34 @@ def enqueue_resource(res, prefix, include_dir)
         @queue << [res, prefix, include_dir]
       end
 
-      def process_resources
-        [@primary, @included].each do |resources|
-          resources.map! do |res|
-            ri = [res.jsonapi_type, res.jsonapi_id]
-            include_dir = @include_rels[ri]
-            fields = @fields[res.jsonapi_type.to_sym]
-            res.as_jsonapi(include: include_dir, fields: fields)
-          end
+      def process_resources(resources)
+        return process_resources_with_cache(resources) if @cache
+
+        resources.map do |res|
+          ri = [res.jsonapi_type, res.jsonapi_id]
+          include_dir = @include_rels[ri]
+          fields = @fields[ri.first.to_sym]
+          res.as_jsonapi(include: include_dir, fields: fields).to_json
+        end
+      end
+
+      def process_resources_with_cache(resources)
+        hash = cache_key_map(resources)
+        cached = @cache.fetch_multi(hash.keys) do |key|
+          res, include, fields = hash[key]
+          res.as_jsonapi(include: include, fields: fields).to_json
+        end
+
+        cached.values
+      end
+
+      def cache_key_map(resources)
+        resources.each_with_object({}) do |res, h|
+          ri = [res.jsonapi_type, res.jsonapi_id]
+          include_dir = @include_rels[ri]
+          fields = @fields[ri.first.to_sym]
+          h[res.jsonapi_cache_key(include: include_dir, fields: fields)] =
+            [res, include_dir, fields]
         end
       end
     end

spec/renderer_spec.rb

@@ -18,6 +18,10 @@ def jsonapi_id
     @id.to_s
   end
 
+  def jsonapi_cache_key(options = {})
+    "#{self.class.name}--#{jsonapi_type}--#{jsonapi_id}"
+  end
+
   def jsonapi_related(included)
     if included.include?(:posts)
       { posts: @posts.map { |p| p } }
@@ -83,6 +87,10 @@ def jsonapi_id
     @id.to_s
   end
 
+  def jsonapi_cache_key(options = {})
+    "#{self.class.name}--#{jsonapi_type}--#{jsonapi_id}"
+  end
+
   def jsonapi_related(included)
     included.include?(:author) ? { author: [@author] } : {}
   end
@@ -142,7 +150,7 @@ def as_jsonapi(options = {})
       data: nil
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders an empty array' do
@@ -151,7 +159,7 @@ def as_jsonapi(options = {})
       data: []
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders a single resource' do
@@ -189,7 +197,7 @@ def as_jsonapi(options = {})
       }
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders a collection of resources' do
@@ -260,7 +268,7 @@ def as_jsonapi(options = {})
       ]
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders included relationships' do
@@ -321,7 +329,7 @@ def as_jsonapi(options = {})
       ]
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'filters out fields' do
@@ -343,7 +351,7 @@ def as_jsonapi(options = {})
       }
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders a toplevel meta' do
@@ -354,7 +362,7 @@ def as_jsonapi(options = {})
       meta: { this: 'is_meta' }
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders toplevel links' do
@@ -365,7 +373,7 @@ def as_jsonapi(options = {})
       links: { self: 'http://api.example.com/users' }
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders a toplevel jsonapi object' do
@@ -382,12 +390,12 @@ def as_jsonapi(options = {})
       }
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 
   it 'renders an empty hash if neither errors nor data provided' do
     actual = JSONAPI.render({})
-    expected = {}
+    expected = ''
 
     expect(actual).to eq(expected)
   end
@@ -412,6 +420,6 @@ def as_jsonapi
                { id: '2', title: 'Works poorly' }]
     }
 
-    expect(actual).to eq(expected)
+    expect(JSON.parse(actual)).to eq(JSON.parse(expected.to_json))
   end
 end